1. Technical Field
The present invention relates to a sealing structure in which a housing is sealed using a displacement member that is displaceable according to change in pressure, and a pressure change detection device which includes the sealing structure.
2. Related Art
For example, JP-A-2000-211152 discloses a device in which a pressure change detection device is used as an ink end detection device for detecting the ink end of a main tank. The pressure change detection device includes a flexible displacement member which forms a part of an ink supply path and which is displaceable according to a change in the pressure occurring in the path, a spring member which is attached to the displacement member and biases the displacement member in a direction opposite to the direction in which the displacement member is displaced according to a drop in pressure occurring in the path, and a displacement detection section which detects the displacement of the displacement member. Further, the displacement member is attached to the main body of the pressure change detection device in a sealing state by means of thermal welding, thereby preventing ink from leaking.
In the device disclosed in JP-A-2000-211152, the displacement member comes into contact with ink, thereby accompanying temporal deterioration. Therefore, regular replacement is necessary. However, when the displacement member is thermally welded to the main body as described above, it is necessary to replace the whole main body. Here, it is considered that the displacement member is not thermally welded to the main body, a sealing section is provided around the displacement member, and the sealing section is compressed in the main body of the pressure change detection device, thereby attaching the displacement member to the main body in the sealing state. In this case, in order for the pressure change detection device to function normally, it is important that pressure does not leak from the sealing section of the displacement member. Therefore, it is necessary to strictly manage the amount of compression in the sealing section by taking the permanent deformation or the like of the sealing section into consideration.
In addition, such a problem is not characteristic of the pressure change detection device, and may occur, for example, in the sealing structure of the ink supply device (liquid supply device) disclosed in JP-A-2010-23423. In the same manner, it is desired to provide a sealing structure in which the permanent deformation of the sealing section is suppressed, and in which a pressure leak from the sealing section is effectively suppressed by strictly managing the amount of compression in the sealing section.